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STI is dedicated to the design, development and manufacturing of high quality ATV and UTV tires. Their engineers are committed to developing tires that meet the highest standards and provide the greatest value to their customers. Rocky Mountain ATV/MC has many kinds of STI ATV tires, made for sand, snow, mud, tracks and trails. You can be sure any tire that Rocky Mountain ATV/MC sells is durable and built to last, but we also strive to provide incredible prices as well.
If you need two STI ATV tires, make sure you check out our ATV Tire and Wheel Builder Package which can save you up to 56%. Simply choose two tires and wheels using our filters search that will find the tires to fit your machine perfectly. Then our trained professionals will mount them for free and get them ready to be shipped along with the free valve stems you receive with your package. In addition, you also receive free ground shipping with any ATV Tire and Wheel Package.
Austin in MO
I am quite happy with these tires. You can't beat them for the price. You won't find a 6 ply radial for 60 dollars anywhere else. They have good all around traction. Not great in deep mud, but it's not a mud terrain tire either.Read All Reviews
Adam in NY
Great tires with lots of thread and traction. Throws dirt into the air! Didn't get to use them much because sold my ATV a few weeks later after installing these tires. I was in love with these tires!! Hope my new ATV tires wear out fast so I can buy these again!!!!!Read All Reviews
ERIC in PA
Tough,heavy 8 ply tires not much wear after 1000 miles. Looks like they will last another 5,000 miles. Next time I will go with bighorn 2 tires because the Honda pioneer 500 has poor suspension and the bighorns are 6 ply and softer.Read All Reviews
Roy in Arizona
I bought these tires because my friends have had good luck with them but I never got 1 full race out of one front and one rear tire, I finished the race with flats. The race was pretty rocky and rough but everyone else didn't have problem with flats like I did. I'll never run these again, I'll use the other 2 tires for spares and that's about it.Read All Reviews
The first thing is that my tires came in very fast. But when it came to selecting a tire, the more i read the more questions i had.I do not have any miles on these STI Black Diamond XTR tires ( 27x9x12 & 27x11x12) yet but they look good and i wanted to give everyone a idea on the sizing/weights.I had Bighorn 2.0 ( 26x9x12 & 26x11x12) with 500 miles on them and plugs in the sidewall. The tread depth on all 4 bighorns were 5/8".The tread depth on the STI are 1" not the 1 1/8" as stated. All 8 tires had 10 PSI in them for these measurements. The rear tires are the excat same diameter even with the tread depth difference. The front STI is 1/4" taller on total diameter. Also both of rear wheels weighed 39 lbs.The front STI was 36lbs and the 2.0 30lbs. The 2.0's with a steel wheels and the STI with a aftermarket aluminum. I guess this means these 27" STI's are actaually smaller than the 26" 2.0's not counting tread depth? Glad i went with 27's. Hope this helps someone.Read All Reviews
Jerry in AZ
We have an off-road tour company with a fleet of 14 UTVs. We have used just about every tire out there and these tires are the worst we have ever used. We put them on the front of a few of our UTVs and we wore through the tread in less than 2 months. Very disappointing and we do not recommend buying this tire unless you are always running in soft ground.Read All Reviews